Flyback　topologies　have　advantages　in　terms　of　low　cost,　fewer　electrical　components,　and　simple　circuit　design.　Semiconductor　devices　in　the　primary　and　secondary　sides　are　regarded　as　major　EMI　noise　sources　in　EMI　propagation　paths.　However,　the　same　transformers　under　different　circuit　configurations　can　bring　different　noise　cancellation　effects　due　to　a　change　of　the　electric　potential　distribution　in　transformer　windings　as　well　as　the　phases　of　the　EMI　noise　sources　in　the　primary　and　secondary　sides.　In　this　paper,　a　CM　noise　cancellation　mechanism　is　investigated.　In　addition,　a　flyback　topology　with　high　side　gate　driving　in　the　primary　side　is　proposed　to　form　a　CM　noise　cancellation　mechanism.　Based　on　the　proposed　flyback　topology,　the　capacitor　compensation　cancellation　technique　can　be　applied　to　lower　the　electromagnetic　interference　(EMI)　noise　level　of　the　designed　converter.　Finally,　the　experimental　noise　spectrums　are　used　to　verify　the　effectiveness　of　the　proposed　flyback　circuit　configuration　scheme.